This invention relates generally to devices and techniques for performing endoscopic surgery.
The use of endoscopes enables minimally invasive surgical procedures to be performed in normally closed body cavities, such as the abdominal cavity. (Endoscopy in the abdominal cavity is referred to as laparoscopy.) The abdominal cavity typically needs to be insufflated prior to performing a laparoscopic procedure to create space between the abdominal wall and organs and arteries in the abdominal cavity. This space permits the various surgical devices to be safely inserted and used. Many other body cavities similarly need to be insufflated to perform an endoscopic procedure.
Verres needles are well known to surgeons for producing an initial entry incision during laparoscopic surgery and injecting gas into the abdominal cavity to insufflate the cavity. A Verres needle generally includes a hollow tube having a sharpened tip and means for injecting insufflation gas through the tube. The first surgical device typically inserted after the Verres needle is the laparoscope. Means for visualizing the insertion of the laparoscope are well known and are manufactured by companies such as Ethicon and Covidien.
A problem inherent with conventional Verres needles is that it has been difficult to precisely control the location of the needle tip while making the initial incision. The positioning of the needle tip during the initial incision is critical because insufflation has not yet been performed at this point in the procedure meaning that the patient's arteries and organs are in close proximity to the inside wall of the body cavity. The procedure can be particularly dangerous to the patient because if the needle tip is inserted too deeply, there is a risk of puncturing an artery, such as the aorta, or an internal organ. On the other hand, the body cavity cannot be insufflated if the needle tip is not fully inserted thorough the inside wall and into the body cavity.
Various attempts have been made to overcome the difficulty of positioning the needle tip during the initial incision. For example, U.S. Pat. No. 4,254,762, issued Mar. 10, 1981 to Yoon, describes a system including an “endoscope means” 10 and a “trocar means” 38 encircling the endoscope means. The trocar means has a sharpened end for puncturing the wall of a body cavity. The endoscope means permits the surgeon to visually monitor the puncture of a body cavity. The endoscope means is also spring-biased in the trocar means. When the sharpened end of the trocar means pierces the wall of a body cavity, the spring bias drives the endoscope means into contact with an abutment on the trocar means, thereby providing an audible signal of the completion of the puncture. Yoon does not specifically describe an endoscope designed to image tissue in contact with the tip of the endoscope. Conventional endoscopes are typically designed to image objects removed from the tip of the endoscope.